1. Field of the Invention
In the art of stereo or three-dimensional relief modelling, such models are produced from flat maps, wherein mountains and other natural terrain features having vertical extent are depicted by such means as contour lines. Contour maps are in turn produced by surveys or from aerial photographs which have been subjected to photogrammetric processing and stereo map plotting.
Stereo relief models are utilized for planning purposes or otherwise in many fields, including but not limited to general survey work and map making, road construction, erosion control, flood control and mining operations.
Further, by utilizing the apparatus and techniques of the subject invention, actual stereo relief models of mathematical functions may be constructed and utilized for research and teaching purposes or otherwise.
2. Prior Art
There are numerous known methods of producing three-dimensional map models of natural terrain features having vertical extent. A preferred method is to use a machine known as a contour pantograph.
The tracing stylus of this pantograph is caused to move in a groove which is the contour line of an etched zinc contour plate. This contour plate must, itself, be constructed from a contour map or other stereo plotting techniques. The follower stylus is in reality a revolving power driven cutter which may be height-adjusted to correspond to any given contour line on the contour plate. The follower stylus cuts into a block of laminated plastic sheets, each of which represents one contour interval. The result is a stepped arrangement on the laminated sheet, which is thereafter filled in with modelling clay so as to represent the terrain as it actually is, rather than by the stepped arrangement. In filling in the stepped contour, unavoidable errors occur.
In addition to the errors which are inherent in the modelling processes currently available, a great amount of time is required to make the contour map, prepare the contour plate, cut the laminated block and finally fill in the contoured steps with clay.
A flexible platen, which can be vertically adjusted at a plurality of surface points, as fully disclosed herein and in my co-pending application Ser. No. 557,612, filed on Mar. 12, 1975, now U.S. Pat. No. 4,005,932, entitled, "Photogrammetric Apparatus, Methods of Use, and Products Produced Thereby", is utilized with suitable conformable materials to form a surface upon which permanent stereo relief models may be molded.
Once the flexible platen has been properly adjusted, as taught in said co-pending application, accurate permanent stereo relief maps may be produced in a matter of minutes.